/*
 * Copyright (C) 2018-2020. Huawei Technologies Co., Ltd. All rights reserved.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package io.hetu.core.hive.dynamicfunctions.examples.udf;

import java.util.Locale;

public class IsEmptyUDF
        extends HiveFunction
{
    public Boolean evaluate(String info)
    {
        boolean flag = (info == null || info.isEmpty());

        if (flag) {
            return true;
        }

        return isNULL(info);
    }

    private boolean isNULL(String str)
    {
        if (null == str) {
            return true;
        }

        return str.trim().toLowerCase(Locale.ENGLISH).equals("null");
    }
}
